Telephone substation ringers



y 2, 1958 J. F. HOUDEK, JR 2,844,767

-'rmnmomz SUBSTATION RINGERS Filed Sept. 29, 1954 The principal object of this inventionis to provide an elficient tuned telephone substation-ringer which is of compactconstruction and. which may be readilyadjusted for efficient operation at any desired one of the frequencies (say 16 to 66'cycles) used infrequency-seleo tive Party-line systems. '1' "1 Inknown telephone ringers; compactness and basic efficiency have been secured by providing an armature which is suspended to move between pole extensions of a single electromagnet and polarized by a relatively short permanent magnet applied between one pole of the electromagnet. and the suspension point" of the armature,-and efliciency has been improved by adding a magnetic'shunt bar of limited cross section tothe structure which pro-=' vides'a shunt path between the'poles of the electromagnet of substantially less flux-carrying capacity than the core of the electromagnet, whereby the reluctance of the electromagnet is .reduced, with a consequent increase in its electrical impedance, in that the air gaps'in the mag neticpath through the permanent magnetandj,thearma-' turedo not appear in the shunt path. 1-7: v I

' In 'a tuned ringer, the preferred-practice is to-suspend the armature on alreed which is of a stiffness accordingto the' frequency to. which the ringer is torespond, and

-to weight the armature or its attached .clapper stem inversely according to frequency. ZEfliciency 'of 'operation moreover requires that the angle of movement, or stroke, of the armature 'be' capable of regulationinversely ac cording to the frequency towhich' thegringer is tuned.

According to the invention, the foregoing principles oficompactness and 'efiiciency are retained in a structure inwhich the air gapbe'twe'en' the tractive pole iac esei the. electromagnet and the armature is readily adjustable to permit a greater or lesser armature stroke. Moreover,

symmetry of armature traction isse'cured by associating one potent the permanent magnet with"substantially the magnetic mid-point of the electromagnet, through associationwith an intermediate portion of the shunt bar, whereby flux from that pole reaches'both pole faces of the electromagnet over similar parallel paths. With the other pole of the permanent magnet closely associated .with the suspension point of the armature, alternating flux through the permanent magnet causes both air gaps to act similarly to induce armature movement.

. Further, according to the-invention, compactness with operating efiiciency is retained by employing an L-shaped electromagnet' core having a winding on one arm and an L-shaped armature rectangularly arranged, with the shunt bar and the permanent magnet disposed within the rectangle, and with the clapper stem extending along one of the sides of the rectangle which is formed by an arm of the armature. The air-gap adjustment according to desired stroke is accomplished by sliding the core of the electromagnet along the diagonal of the rectangle which extends .between the armature bend and the core bend, end extensions of the shunt bar closely overlapping the core extremities to maintain magnnetic continuity.

Other objectsand features of the invention be come apparent asthe description progresses.

The accompanying drawings, comprising F138." 1 to show a tuned ringer embodying the principles of the invention.

Figs. 1 and 2 show respectively a top view and an view of the device.

Fig. 3 is aside view of the device with the coil re-,

moved and portions broken able gong mounting feature. I t V Figs. 4 and 5 showrespectivelya side view and amend away to illustrate the'adjust- View of the stroke-adjusting stud. v I j The ringer disclosed in thedrawings comprises a frame which may be die cast of any 'suitablenon magnetic material. The frame'isessentially ;a spider-like, integral formation consisting of a central portion, two substantially parallelly disposed arms projecting atright angles from the upper and lower ends, respectively of the central portion, and a pair of shelf-like integral projections 52. As clearly indicated in Fig. 1, the projections 52 of the frame occupy different horizontal planes. "The parallel arm portions of the frame are joined by one arm of v i a generally L-shapedcore Shaving a -coil 4 slidably mounted thereon to occupy the space between the arms oftheframei The coil 4 is provided with the usual coil terminals to enable it to be incorporated in a ringer circuit.

The core 5 preferably con'sists 'of a plurality of lamii nations and is rigidly secured together by tabs 70, of

slide plate 6 whichgmay be formed ofany suitable non-magnetic material. As indicated in Figs-land};

the tabs 70 are integral projections of plate 6. 1

The magnet assembly consisting of plate 6, core 5, and} coil 4 is slidably secured to the'frame by'integral raised guide portions, of frame 2, and by means of screw passing through an elongated opening in 6 to threadedly engage frame 2.

The shunt bar 7,' which isoffrnag'netic materialyisi I fixedto the frame by means'offscrews 22.; This 619-. ment, which is formed generally in an L -shape', is clearly' shown in Fig. 1;. Bar 7 consists of two aimsfjltl and 20,

interconnected byportion 19, terminating in' extensions 21 which' overlappinglyengag'es the extremitiesiof core 5. As shown in Fig. 1, -a rectangular shaped permanent magnet 3'is secured to the frame betweenlP'ostsSO by a non-magnetic plate '15 and screws. 16. Theinorth pole of magnet 3, for example,[abuts portion 19'Iof shunt bar V 7 while its south'poleis associated with portion of armature24: I it The armature assembly 8 adapted to vibrate under controlof coil '4' ispivotably mount on raised-portion 51 offrame2-. 1.l':rl. l V. ilma;

As indicated in Fig. l, armature 24 of assembly 8, is of a generally L-shaped configuration having tractive arms 25 and 27 interconnected by an enlarged portion-24 which is associated with magnet 3.

Reed 34 and clapper-rod bracket 32 are secured to the lowerportion-of tractive arm 25 (Figs. 1 to 3)'-by'means of screws 33. Clapper rod 29 is rigidly secured into the circular portion of 32, as'by knurling or welding. Rod 29 j is provided with clapper 30 for striking the gongs 9 alternately, the clapper being slidably secured to rod 29, as

by the indicated setscrew 31, to facilitate tuning of'the armature assembly. Reed 34 is secured at its lower end to portion '51 of frame 2, between'spaced blocks 35 and 36 by means of screws 37. 1 7

Each shelf-ledge like section 52 (Fig. 3) carries simioffset with respect to the longitudinal axis of shaft 44 so that as the gong mounting is rotated on shaft 44 the spacing between gongs 9 is increased or decreased depending upon the direction in which the assembly is rotated. Base 42 is provided with a circular ledge portion which is engaged by the, of resonator which is rigidly secured to post 43. Gong9 is mounted. onpost 43 in telescopic relationto its associated resonator 46 and is secured to post 43 by means of a screw 41 which passes through an aperture in gong 9, through lock washer 48, into a suitably tapped hole in post 43. The gong assemblies are rotatably secured to frame sections 52 by means of screws 47 passing through elongated openings 54 (Fig. 2) of sections 52, through washers 49, into a suitably tapped hole in 42. The circular base members 42 are provided with integral tab portions 45 which cooperate with notches 53. of sections 52 to increase or decrease the spacing between gongs as will be hereinafter described.

To'provide a ringer. tuned to any desired frequency a reed 34 of suitable thickness is selected, and a clapper 30 having a suitable mass is selected and placed approximately in location shown in Figs. 1 and 3. Reed 34 is provided with elongated openings (not shown) which permits the armature 8 to be moved to provide equal operating air gaps. The magnet assembly is next adjusted to provide a preliminary stroke gap according to the frequency in question. This is readily accomplished by loosening lockscrew 60 and then rotating stud 61 until the desired setting is obtained whereupon locking screw 60 may be retightened.

As shown in Figs. 4 and 5, shaft 62, of stud 61, is eccentrically located and upon rotating the stud its head portion engages the edge of elongated opening 71 of plate 6 to move the magnetic assembly, angularly as viewed in Fig. 1 up and to the left. The motion of the assembly is guided by raised integral guide portions of frame 2. Stud 61 passes through an aperture in frame 2 and is secured thereto by a spring washer or a speed nut (not shown) which engages under-cut portion 63 to prevent its Withdrawal.

After the preliminary gap adjustments are made and with the gongs 9 moved out of engagement with clapper 30 a low voltage (at the desired frequency) is applied to the winding to adjust for maximum sensitivity. This is done by locating clapper 30 on clapper rod 29 at the point giving the most vigorous response, whereupon screw 31 is tightened firmly holding the clapper in position. With the low voltage applied to the winding the eccentrically mounted gongs 9 are rotated to a position that they are struck with equal force by clapper 30.

The adjustment of the space relationship between gongs 9 and clapper 30 is readily accomplished by loosening screw 47 and inserting a tool, such as a screw-driver blade between tabs 45 to engage one of the notches 53 and then rotating the tool until the desired adjustment is obtained whereupon screw 47 is retightened.

Following-the sensitivity adjustment the ringer is further adjusted with full ringing current applied to the winding as to interference, balance, and tone. This adjustment is readily accomplished by readjusting the magnet assembly to vary the air gap between armature 24 and core 5 and readjusting the location of the gongs.

I claim:

1. A polan'zed electromagnetic device including a winding, a magnetic core for'the Winding, and an armature, with operating air gaps between armature and core, the core and armature being cooperatively arranged in the general form of a rectangle, means for suspending the armature for a turning movement about an intermediate portion thereof. to shorten either said gap while lengthening the other, a magnetic shunt bar and a permanent magnet located within the rectangle, the shunt bar shunting the core, the permanent magnet extending from an intermediate portion of the shunt bar to a point close to the said intermediate portion of the armature to polarize the armature with respect to the core, the armature and the core each comprising a generally L-shaped portion with the operating air gaps being located at diagonally opposed corners of the said rectangle, means for guiding the core for movement along the armature-core diagonal of the rectangle to regulate the length of the said operating air gaps, the shunt bar slidingly overlapping the extremities of the core to maintain uniform shunting of the core in its several adjustment positions.

2. A polarized electromagnetic device including a winding, a magnetic core for the winding, and an armature, with operating air gaps between armature and core, means for suspending the armature for a reciprocal movement to shorten either said gap while lengthening the other, a magnetic shunt bar shunting the core, a permanent magnet extending from an intermediate portion of the shunt bar to a point close to a portion of the armature to polarize the armature with respect to the core, means for guiding the core for movement toward and away from the armature to regulate the length of the said operating air gaps, means for maintaining the shunt bar and permanent magnet fixed during any such adjustment movement of the core, the shunt bar slidingly overlapping the extremities of the core to maintain uniform shunting of the core in its several adjustment positions.

References Cited in the file of this patent UNITED STATES PATENTS 2,013,229 Andis Sept. 3, 1935 2,375,586 Romer May 8, 1945' 2,380,293 Cari-all July 10, 1945 2,579,261 Indergand Dec. 18, 1951 2,692,380 Cleaveland Oct. 19, 1954 2,716,232 Power Aug. 23, 1955 Patent No 2,844,767

UNITED STATES PATENT OPFlF-F,

(IERTEFICATE 9F CORRECTIQN July 22, 1958 Joseph F. Houdek, Jr. It'is hereby "certified that egaror appears in the above numhered 1 patent requiring correction and that the said Letters Patent should read as corrected below.

In the grant, lines 2 and 12, and in the heading to the printed specification, lines 3 and 4; name of assignee, for "international Telephone and Telegraph Company", in each occurrence, read International Telephone and Telegraph Corporatio Signed and sealed this 18th day of November 1958n (SEAL) Attest:

KARL H, AXLINE Attesting Offiicer ROBERT C. WATSUN Commissioner of Patents specification, lines 3 and 4, name of assignee, for "international Telephone and Telegraph Corporation UNITED STATES PATENT OFFICE CERTKFICATE @F CQRRECTEQN Patent No 2,844,767 July 22, 1958 I Joseph Fg'fioudek, Jr.

It is hereby certified that error appears in the above numbered patent'requiring correction and that the said Letters Patent should read as corrected below.

"In the grant, lines'2*and l2, and in the heading to the printed Telephone and Telegraph Company", in each eceurrenee, read me International Signed and sealed this 18th day of November 1958,

(SEAL) Attest:

KARL MINE ROBERT c. WATSON Attesting Officer Conmissioner of Patents 

